GI

a member or former member of the U.S. armed forces, especially an enlisted soldier.

adjective

2.

rigidly adhering to military regulations and practices; regimented; spit-and-polish:

a platoon leader who tried to be more GI than anyone else.

3.

of a standardized style or type issued by the U.S. armed forces:

GI shoes; GI blankets.

4.

conforming to the regulations or practices of the U.S. armed forces:

Every recruit must get a GI haircut.

5.

of, relating to, or characteristic of a U.S. enlisted person:

a typical peacetime GI complaint.

verb (used with object), GI'd, GI'ing.

6.

to clean in preparation for inspection:

to GI the barracks.

verb (used without object), GI'd, GI'ing.

7.

to follow military regulations and customs closely; shape up:

You'd better learn to GI if you want to be promoted.

Also, G.I.

Origin

1915-20; orig. abbreviation of galvanized iron, used in U.S. Army bookkeeping in entering articles (e.g., trash cans) made of it; later extended to all articles issued (as an assumed abbreviation of government issue) and finally to soldiers themselves

gi

in measurement, unit of volume in the British Imperial and United States Customary systems. It is used almost exclusively for the measurement of liquids. Although its capacity has varied with time and location, in the United States it is defined as half a cup, or four U.S. fluid ounces, which equals 7.219 cubic inches, or 118.29 cubic cm; in Great Britain the gill is five British fluid ounces, which equals 8.669 cubic inches, one-fourth pint, or 142.07 cubic cm.